fix(examples-py): validate Groq, Guardrails, and Haystack OTel 2.x spans

[Nightingalelyy]

What changed

• link the Groq, Guardrails, and Haystack examples to their local Respan packages
• add exact shared run markers, bounded workflow content, activation checks, and explicit shutdown
• add complete batch runners for all three example sets
• bootstrap the managed Haystack prompt before the dependent prompt-ID scenario
• constrain Haystack examples to the validated 2.x/OpenInference 0.1.x line

Why

The instrumentation fixes require repeatable end-to-end examples that fail visibly on activation problems and can be queried as one exact MCP validation batch.

Impact

The three example sets now provide deterministic grouped validation for stream/tool, context propagation, direct components, pipelines, async paths, gateway LLMs, managed prompts, and controlled negative cases.

Validation

• Black, Ruff, and git diff --check pass
• all 52 examples passed with the repository .env credentials and locally linked packages
• Respan MCP inspected all 52 trace trees and 210 full records under otel2-fix-py-group-14-20260817T035735Z